<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script type="text/javascript" src="./js/ctx.js"></script>
</head>
<style>
    #cesiumContainer {
        display: flex;
        width: 100%;
        height: 100%;
    }
    #view3D {
        display: inline-block;
        width: 100%;
    }
    #view2D {
        display: inline-block;
        width: 100%;
    }
</style>
<body>
<div id="cesiumContainer">
    <div id="view3D"></div>
    <div id="view2D"></div>
</div>
<div id="toolbar"></div>
<script>
    var initCesium = new InitCesium();

    // We want our two views to be synced across time, so we create
    // a shared clock object that both views share
    var clockViewModel = new Cesium.ClockViewModel();
    var options3D = {
        fullscreenButton : false,
        sceneModePicker : false,
        clockViewModel : clockViewModel
    };
    var options2D = {
        homeButton : false,
        fullscreenButton : false,
        sceneModePicker : false,
        clockViewModel : clockViewModel,
        infoBox : false,
        geocoder : false,
        sceneMode : Cesium.SceneMode.SCENE2D,
        navigationHelpButton : false,
        animation : false
    };
    // We create two viewers, a 2D and a 3D one
    // The CSS is set up to place them side by side
    var view3D = initCesium.initViewer('view3D', options3D);
    var view2D =  initCesium.initViewer('view2D', options2D);

    var worldPosition;
    var distance;

    function sync2DView() {
        // The center of the view is the point that the 3D camera is focusing on
        var viewCenter = new Cesium.Cartesian2(Math.floor(view3D.canvas.clientWidth / 2), Math.floor(view3D.canvas.clientHeight / 2));
        // Given the pixel in the center, get the world position
        var newWorldPosition = view3D.scene.camera.pickEllipsoid(viewCenter);
        if (Cesium.defined(newWorldPosition)){
            // Guard against the case where the center of the screen
            // does not fall on a position on the globe
            worldPosition = newWorldPosition;
        }
        // Get the distance between the world position of the point the camera is focusing on, and the camera's world position
        distance = Cesium.Cartesian3.distance(worldPosition, view3D.scene.camera.positionWC);
        // Tell the 2D camera to look at the point of focus. The distance controls how zoomed in the 2D view is
        // (try replacing `distance` in the line below with `1e7`. The view will still sync, but will have a constant zoom)
        view2D.scene.camera.lookAt(worldPosition, new Cesium.Cartesian3(0.0, 0.0, distance));
    }

    // Apply our sync function every time the 3D camera view changes
    view3D.camera.changed.addEventListener(sync2DView);
    // By default, the `camera.changed` event will trigger when the camera has changed by 50%
    // To make it more sensitive, we can bring down this sensitivity
    view3D.camera.percentageChanged = 0.01;

    // Since the 2D view follows the 3D view, we disable any
    // camera movement on the 2D view
    view2D.scene.screenSpaceCameraController.enableRotate = false;
    view2D.scene.screenSpaceCameraController.enableTranslate = false;
    view2D.scene.screenSpaceCameraController.enableZoom = false;
    view2D.scene.screenSpaceCameraController.enableTilt = false;
    view2D.scene.screenSpaceCameraController.enableLook = false;
</script>
</body>
</html>